山东省沿海地区淡色库蚊感染沃尔巴克氏体的初步调查研究

Primary investigation on infection of Wolbachia in Culex pipiens pallens in coastal areas of Shandong Province

目的了解山东省沿海地区淡色库蚊种群中沃尔巴克氏体(Wolbachia)的感染情况及其分型,为蚊媒疾病防治提供新的研究方向和理论基础。方法2022年6月—2023年8月,利用灯诱法采集山东省的烟台市莱州市、烟台市龙口市、青岛市黄岛区、青岛市崂山区、日照市五莲县、日照市东港区、东营市河口区及东营市东营区共8个采样点的蚊媒样本,采用形态学和分子学相结合的方法鉴定出淡色库蚊自然种群样本。然后利用沃尔巴克氏体的表面蛋白(Wol⁃bachia surface protein,wsp)基因序列建立的PCR检测方法,对上述8个采样点的淡色库蚊样本进行沃尔巴克氏体感染率的检测。同时,从GenBank数据库中下载沃尔巴克氏体的代表株系,利用Mega5.2软件对所获基因序列进行系统发育分析以分型。结果山东省4个沿海城市均发现有沃尔巴克氏体的感染,平均感染率为80.8%(261/323);其中烟台市的感染率最高,为100%(46/46);日照市五莲县的感染率最低,为60.6%(20/33)。共计发现12种wsp单倍型,其中Hap1的感染率为92.5%,Hap2的感染率为70.0%,而其他单倍型的感染率则较低。从单倍型来源来看,在8个采样点中均检测出单倍型Hap1,其他单倍型仅在部分采样点地理种群检测到。其中,东营市东营区检测出的单倍型多样性最高,为6种。经系统发育树分析得出结论,8个采样点感染的沃尔巴克氏体均属于B型。结论山东省沿海地区的淡色库蚊种群以感染B型沃尔巴克氏体为主,但是不同地区感染的沃尔巴克氏体的单倍型存在差异,本调查可为这些地区特定蚊媒疾病的精准防控提供一定理论基础。

Objective To understand the infection status and typing of Wolbachia in Culex pipiens pallens population in coastal areas of Shandong Province,and to provide new research directions and theoretical basis for the prevention and control of mosquito-borne diseases.Methods From June 2022 to August 2023,mosquito samples were collected from 8 sites in four coastal cities of Yantai,Qingdao,Rizhao,and Dongying in Shandong Province by light lure method.The collected samples were identified as Culex pipiens pallens by combining morphological and molecular methods.Then,using the PCR detection method established by the Wolbachia surface protein(wsp)gene sequence,the Wolbachia infection rate of Culex pipiens pallens collected in the field from 8 sites along the coast of Shandong Province was detected.In addition,the representative strain of Wolbachia was downloaded from the GenBank database,and the obtained gene sequences were subjected to phylogenetic analysis using Mega5.2 software for typing.Results Wolbachia infection was found in all four coastal areas of Shandong Province,with an average infection rate of 80.8%(261/323).Among them,Yanti had the highest infection rate of 100%(46/46),while Wulian County,Rizhao City had the lowest infection rate of 60.6%(20/33).A total of 12 wsp haplotypes were identified,with 92.5%infection rates for Hap1,70.0%for Hap2,and lower rates for Hap3 to Hap12.From the perspective of haplotype sources,Hap1 was detected in all 8 sampling sites,while other haplotypes were only detected in some geographical populations of sampling sites.Among them,Dongying District,Dongying City had the highest haplotype diversity,with six haplotypes detected.Phylogenetic tree analysis concluded that the Wolbachia strains found in all eight sampling points belonged to group B.Conclusions Infection of Wolbachia group B is common in Culex pipiens pallens in coastal areas of Shandong Province.Still,there are certain differences in the haplotypes of Wolbachia infections in different regions.This provides a valuable theoretical basis for targeted prevention and control of specific mosquito-borne diseases in the region.